Quick release spring latch for hearing aid casing



June 2 1970 M. M. VAN DER PAS 3,515,822

QUICK RELEASE SPRING LATCH FOR HEARING AID CASING Filed Julyfi, 1966FIG.1 FIG.2

INVENTOR. MARTINUS M.VAN DER PAS United States Patent U.S. Cl. 179179 3Claims ABSTRACT OF THE DISCLOSURE A hearing aid casing having twocomplementary shaped enveloping lids for containing therebetween thecomponent parts of the hearing air. The lids are held together in aclosed position by a wire spring within the casing which can be releasedfrom without through an aperture formed in the bottom by the lids.

The invention relates to a casing, more particularly for a hearing aid,consisting of a frame and at least one lid, one edge of which isprovided with a tag hooked into the frame, while the opposite edge issecured to the frame by means of a bolt member. This structure has theadvantage that the lidsgenerally two-can be entirely smooth on the outerside, which permits of carrying the apparatus beneath the clothes or ina pocket thereof.

Hearing aid casings of the prior art usually have bolt members forjoining the two lids of the casing. These bolt members are slidablyjournalled on the frame and are tightened by means of screws. Adisadvantage of this arrangement is that the screws frequently loosen aswhile the case is being carried in a pocket or other place beneath theclothes.

The construction in accordance with this invention does away with theconventional bolt member fastening means and in its place uses a wirespring which clamps the two lids in a closed position. An objecttherefore of this invention is to provide a simplified construction fora hearing aid casing.

An embodiment of the invention is shown in the accompanying drawing, inwhich:

FIG. 1 is a cross-sectional view taken on a plane parallel to the largesurfaces of the flat casing, while FIG. 2 is a cross-sectional viewtaken on the line IIII of FIG. 1.

The drawing shows the metal casing of a hearing aid to be carried at orbeneath the clothes (a so-called pocket device). The casing has a metalframe consisting of a substantially strip-shaped part 1 to one end ofwhichin the drawing to the lower enda base part 3 is secured whichextends at right angles to the longitudinal direction of the strip 1.The strip-shaped frame part 1 supports a preferably insulating chassisplate 5 on which are mounted a plurality of component parts of thehearing aidwhich are not shown for the sake of clarity. The casing ofthe device further consists of two preferably identical adjoining lids 7and 9 the first of which will be described more fully hereinafter.Instead of consisting of a frame and two lids, as shown, the casingcould also consist of a frame which at the same time constitutes onehalf of the casing and one lid fitting thereto.

The slightly box-shaped lid 7 is at one of its edgesin this case at theupper edgeprovided with a securing tag 11 which is hooked together witha corresponding tag on the other lid 9 into a fitting slot 15 formed ina rectangularly bent portion 13 of the frame part 1. The opposite-4nthis case the lower-edge of the lid 7 is secured to the 3,515,822Patented June 2, 1970 "ice frame part 3 by means of a wire spring 17substantially extending along the said lower edge. At least one of theends of the wire spring 17 yields freely and is located under a springpressure parallel to the lid 7 and directed towards the said lower edgebetween a tag 19 formed on this lower edge and a tag 21 extending inopposite direction formed on the frame part 3. As shown in the figures,the tag 19 is bent over towards the inner side of the lid 7, while thetag 21 has two extended portions each located on either side of the tag19, completely engages the inner surface of the lid and consists of aportion of the downwardly protruding or looking edge of the box-shapedframe part 3. The wire spring 17, at its resilient free end, is clampedbetween the tags 19 and 21, tag 19 being directed obliquely towards thecentre of the box, as shown in FIG. 2. The downwardly directed springpressure pushes the comparatively stiff wire spring 17 into thewedge-shaped space (see FIG. 2) between the tags 19 and 21, whichresults in the lid being drawn tightly and in a rattle-free manneragainst the edge of tag 21 of the frame part.

The wire spring 17 is preferably U-shaped and its two respective limbsserve for securing the two lids 7 and 9. The base portion 23 of theU-shaped wire spring is secured to the lower side of the frame part 3,for example, by means of a few tags 25 cut out of this frame part; asshown in FIG. 1, each of the limbs of the wire spring has a kink andeach limb engages in the kink point in a direction opposite the saidspring pressure the lower side of the frame part 3.

The wire spring is accessible through an aperture 27 provided in thelower edges of the two lids 7 and 9; in normal operation, this apertureis closed, for example, by a pivotal lower lid locked by means of acatch (which is not shown for the sake of clarity). If the lid 7 shouldbe detached, as after opening the casing, the freely yielding end of thesaid wire spring 17 is lifted against the spring pressure out of thesaid wedge-shaped space between the tags 19 and 21 and placed on theother side of the tag 19. The tag 19 can now pass unhindered through therecess between the tag portions 21 and subsequently the tag 11 formed onthe upper edge of the lid can be hooked out of the slot 15 without theuse of further means. The lid 7 is secured in that, after this lid hasbeen put in place, the freely yielding end of the wire spring 17 isagain placed between the tags 19 and 21.

It is apparent from the foregoing that the structure described consistsof relatively few component parts which are simple in construction, andowing to the pressure exerted by the spring, the lids cannot be detachedunintentionally.

In a modification of the embodiment described in which the wire springis U-shaped, the spring consists of two separate substantially straightwires. The spring wire associated, for example, with the lid 7 may besecured either to one of the tag portions 21 or to an additional tag tobe formed beside the tag 19 on the lower edge of the lid 7. In thisalternative embodiment, the tag 19 is parallel to the lid 7 and thespace between the tags 19 and 21 is shaped into the form of a wedge inthat the tag 21 or at least its parts adjacent the tag 19 are slightlybent inwards. In the position shown in FIG. 2, however, the bolt spring17 can be more readily lifted and then closed again.

The lid 7 can be detached most easily if the tag 21, as shown in FIG. 1,consists of two extended portions each located in a direction on eitherside of tag 19 which allow the lip to pass freely between them. Theaperture of passage may alternatively be slightly shifted, provided thatthe structure is such that, after the spring has been detached, the lidcan be displaced through a corresponding distance.

A modified construction is feasible having only one tag 21 also fallwithin the scope of the invention, which tag may also be directedupwards instead of downwards; however, a stronger spring 17 is thengenerally required, since this spring is supported only on one side ofthe tag 19.

What is claimed is: 1. A spring latch locking arrangement for a hearingaid casing comprising a frame member for supporting the component partsof the hearing aid, two substantially parallel lid members envelopingthe frame member, said lid members having upper and lower edges andremovably engageable along their upper edges to the frame member, tagmembers formed from inwardly directed portions of the lower edges ofeach of the lid members, said tag members being positioned for coactingwith openings formed on either side of the frame member by extendedportions of said member, a wire spring attached to the frame memberhaving resilient legs engageable between the extended portions of theframe member and the tag members to urge the respective lid memberstogether and to prevent their separa- 4 tion by blocking the openingformed by the extended portions of the frame.

2. A spring latch locking arrangement for a hearing aid casing asclaimed in claim 1 wherein the lower edges of the lid members define anaperture therebetween for providing access to the wire spring forengagement or disengagement of the resilient legs.

3. A spring latch locking arrangement for a hearing aid casing asclaimed in claim 1 wherein the wire spring has a U shape, with each ofthe legs of the U having a kink which engages the frame member to biasthe ends of the legs toward the tag members.

3/1950 Posen 179-107 KATHLEEN H. CLAFFY, Primary Examiner 20 T. W.BROWN, Assistant Examiner UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent N Dated June 2 Inventors MARTINUS MARINUS VAN DER PASIt is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 1, line 18, "air" should be aid- Column 3, line 1, delete "alsofall within the scope of the invention" SIGNED AND semen sez m fiEAL) Ammm'am'mewhcrk mm 1:. I m. Attesting Officer Gomissioner of Patents FORMPO-105O [10-69) USCOMM,DC 50375 pflg 0 u s GOVEINMENY murmur, crnc: I9!O-Jii-l

